Molecular detection of efflux pump and virulence factors genes in Pseudomonas aeruginosa

Document Type : Original Article


1 Department of Medical Microbiology and Immunology, Faculty of Medicine, Sohag University, Egypt

2 Department of Clinical and Chemical Pathology, Faculty of Medicine, Sohag University, Egypt

3 Department of Tropical Medicine and Gastroenterology, Faculty of Medicine, Sohag University, Egypt

4 Department of Chest Diseases and Tuberculosis, Faculty of Medicine, Sohag University, Egypt.


Background: Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic virulent bacterium with natural resistance to several antibiotics. It is an important causative agent in respiratory tract infections, surgical wound infections, burn wounds, and urinary tract infections. It has many virulent factors enhancing its pathogenesis e.g., tox A, type III secretion system that play a crucial role in tissue destruction.  Pseudomonas aeruginosa is resistant to many antibiotics through different mechanisms including the availability of an efflux pump that extrudes antibiotics outside the bacteria. Numerous efflux genes are discovered e.g., MexAB-OprM, MexCD-OprJ, or MexXY (-OprA). Aim of work: To investigate some of the virulence genes and efflux pump genes in P. aeruginosa and to estimate their impact on antibiotic resistance. Methods: This current study was conducted on 250 different samples (sputum, urine, surgical wound, and burns) culture and sensitivity were done to the isolated bacteria, then molecular detection of efflux pump and some virulence genes by PCR. Results: Out of 250 samples, 46 yielded P. aeruginosa. These 46 samples were collected from 22 males and 24 females. Forty percent of the isolates were resistant to ceftazidime and cefepime followed by 37% resistance to ofloxacin and 36% resistance to gatifloxacin. Imipenem was the most susceptible antibiotic. Of all the isolated Pseudomonas 87% were multidrug-resistant.  Exotoxin S (Exo S) gene was found predominantly in surgical wound samples 10 (21.7%), followed by burn samples, and sputum samples. Conclusion: There was a significant association between the availability of efflux genes and antibiotic resistance in Pseudomonas.  Pseudomonas aeruginosa carries multiple mechanisms to destroy human cells and to compete with antibiotics, knowing these factors may be helpful to counteract them by targeting virulence or inhibiting efflux mechanisms.


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